A279968 Square array read by antidiagonals upwards in which each term is the number of prior elements in the same row, column, diagonal, or antidiagonal whose parity is not the same as the parity of n.
0, 0, 2, 0, 4, 0, 3, 1, 4, 2, 3, 3, 5, 3, 4, 2, 3, 5, 5, 4, 7, 2, 4, 5, 5, 6, 8, 3, 5, 4, 5, 10, 7, 7, 7, 7, 5, 5, 5, 9, 6, 12, 6, 8, 9, 4, 5, 8, 6, 6, 10, 9, 9, 7, 10, 4, 6, 8, 8, 5, 13, 9, 9, 12, 12, 8, 7, 6, 7, 8, 10, 9, 10, 12, 7, 11, 14, 9
Offset: 1
Examples
The first six terms of this array are: . 0 2 0 0 4 0 . a(8) = 1 because the parity of 8 is different from the parity of a(7) = 1. a(3) = 2 because the parity of 3 is different from the parity of a(2) = 0 and a(1) = 0.
Links
- Peter Kagey, Table of n, a(n) for n = 1..5000
Crossrefs
Programs
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Haskell
a279968 n = genericIndex a279968_list (n - 1) a279968_list = map count [1..] where count n = genericLength $ filter (odd . (n+)) adjacentLabels where adjacentLabels = map a279968 (a274080_row n)